â¤0.2 mg/dL. Measurement of the levels of bilirubin is used in the diagnosis and treatment of liver, hemolytic, hematologic, and metabolic disorders, including hepatitis and gall bladder obstruction. The assessment of direct bilirubin is helpful in the differentiation of hepatic disorders.
Ritchie Valens. In an all too brief career, Ritchie Valens was the first Chicano rock and roll star, having his best remembered hit, La Bamba, just one month before his untimely death with Buddy Holly and the Big Bopper on February 3, 1959.
LEAD: WE already know as much about Ritchie Valens's brief life as we learn from ''La Bamba,'' the film biography that traces his early love of music, his dizzying rise to stardom and his tragic death in a plane crash.